1. Field of the Invention
The present invention relates to a sealed body including two substrates and a method for manufacturing the sealed body. Further, the present invention relates to a light-emitting device including an organic EL element and a method for manufacturing the light-emitting device.
2. Description of the Related Art
A technique in which a highly airtight sealed body is formed in such a manner that two substrates are bonded to each other by glass frit (also referred to as frit glass) including low-melting glass is known. In a technique disclosed in Patent Document 1, a paste containing a binder and a frit material including low-melting glass is applied to a glass substrate along an edge of the glass substrate, the binder is removed and the frit material is melted to form glass frit by baking of the paste, the glass frit is irradiated with laser light with the substrate overlapping with a counter substrate, and the glass frit is melted so that the substrate and the counter substrate are bonded to each other by the glass frit; thus, a highly airtight sealed body is formed.
Since glass frit has a high gas barrier property, a space sealed with the glass frit can be kept away from the external atmosphere. A method for sealing with such glass frit is used for a device including an element, such as an organic EL element, whose performance is rapidly decreased once the element is exposed to air (including moisture, oxygen, or the like).
As examples of the device including the organic EL element, a lighting device, an image display device in which a thin film transistor and an organic EL element are combined, and the like can be given. Since the organic EL element can be formed into a film and a large-area organic EL element can be easily formed, a lighting device including a planar light source can be provided using the organic EL element. Further, since a backlight is not needed for an image display device including the organic EL element, the image display device can be thin and light weight, and have high contrast.